Polyurethanes are compounds useful in many applications, including but not limited to high performance adhesives, surface coatings and sealants, binders, hydrogels, and resins. A polyurethane compound is any polymer composed of a chain of organic units joined by carbamate (—NCOO—) links. Polyurethanes are conventionally formed in the reaction of a diisocyanate and polyfunctional compounds typically containing numerous hydroxyl groups, such as a diol, in the presence of a catalyst. However, a disadvantage to this synthetic route is the use of monomers having numerous toxic isocyanate groups.
Recently, some attention has been focused on the synthesis of polyurethanes without the use of isocyanate groups through the reaction of a diamine and a molecule having one or more cyclic carbonate functional groups in the presence of a solvent and catalyst. This reaction results in compounds often referred to as polyhydroxy urethanes (PHUs) due to the presence of primary and/or secondary hydroxyl functional groups.